I found this documentation for Oracle DECIMAL data type: 
https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/Data-Types.html#GUID-75209AF6-476D-4C44-A5DC-5FA70D701B78,
 which explains what a SCALE > PRECISION should mean.

> Scale can be greater than precision, most commonly when e notation is used. 
> When scale is greater than precision, the precision specifies the maximum 
> number of significant digits to the right of the decimal point. For example, 
> a column defined as NUMBER(4,5) requires a zero for the first digit after the 
> decimal point and rounds all values past the fifth digit after the decimal 
> point. 

Let me ask a related question: in my backend I want to reject such numbers. 
What is the right way to do it?
Should this be done in a SqlShuttle? Or should some Validator class be 
extended? 

Thank you,
Mihai

-----Original Message-----
From: Julian Hyde 
Sent: Sunday, August 06, 2023 2:19 PM
To: [email protected]
Subject: Re: DECIMAL(2, 3) meaning

As I commented in https://issues.apache.org/jira/browse/CALCITE-5901, I don’t 
think it’s a bug to support behavior beyond what the standard requires. Which 
Calcite does, intentionally. 

Julian

> On Aug 6, 2023, at 08:35, stanilovsky evgeny <[email protected]> 
> wrote:
> 
> Ok, seems like a bug.
> Feel free to fill the issue.
> 
>> I have added this test to SqlOperatorTest:
>> 
>>    f.checkScalar("cast(0.012 as DECIMAL(2, 5))", new BigDecimal("0.012"),
>>        "DECIMAL(2, 5) NOT NULL");
>> 
>> and it has passed. That's why I am asking. It should fail, but it doesn't.
>> 
>> Mihai
>> 
>> -----Original Message-----
>> From: stanilovsky evgeny
>> Sent: Friday, August 04, 2023 7:00 AM
>> To: [email protected]
>> Subject: Re: DECIMAL(2, 3) meaning
>> 
>> Hello Mihai.
>> A bit older standard describes Precision as : Precision of decimal 
>> floating-point values is a positive value that specifies the number of 
>> significant decimal digits in the mantissa.
>> 
>> Thus:
>> cast(0.012 as DECIMAL(3, 3)) - ok
>> cast(0.012 as DECIMAL(2, 3)) - fail
>> cast(0.012 as DECIMAL(1, 3)) - fail
>> cast(0.012 as DECIMAL(2, 5)) - fail
>> 
>> 
>>> Hello,
>>> 
>>> 
>>> I notice that Calcite happily accepts decimal type specifications 
>>> where the scale is greater than the precision.
>>> 
>>> There are quite a few tests with such types.
>>> 
>>> 
>>> What is the meaning of such types?
>>> 
>>> 
>>> The SQL 92 standard has this statement on page 109:
>>> 
>>> 
>>> 15)The <scale> of an <exact numeric type> shall not be greater than
>>> 
>>>            the <precision> of the <exact numeric type>.
>>> 
>>> 
>>> Thank you,
>>> 
>>> Mihai

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